1. Field of the Invention
The present invention generally relates to feed material mixing and, more particularly, is concerned with a feed material mixing apparatus incorporating improvements in the arrangement of the mixing components of the apparatus and the control of their operating speeds.
2. Description of the Prior Art
In the preparation of feed for livestock consumption, it is conventional practice to mix various types of feed materials together with one another or with a suitable additive, such as molasses or some other liquid. For proper quality, it is imperative that such feed materials be thoroughly mixed at the proper speed.
One feed material mixing apparatus utilized heretofore for preparation of livestock feed is described and illustrated originally in U.S. Pat. No. 3,129,927 to Mast and more recently in U.S. Pat. No. 4,509,862 to High et al. Both of these patents are assigned to the assignee of the present invention. The mixing apparatus disclosed in these patents generally includes a tank having vertical front and rear end walls, upwardly diverging side walls and an arcuate bottom wall. Disposed above the bottom wall is a rotatably-mounted horizontal bottom auger which extends fore-and-aft between the tank front and rear end walls. Flights on forward and rearward portions of the bottom auger spiral in reversed relation such that rotation of the bottom auger conveys feed material away from the front and rear end walls of the tank and toward an intermediate location along the bottom auger. A pair of rotatably-mounted vertical augers are disposed adjacent opposite sides of the bottom auger at such intermediate location therealong. Respective flights of the vertical augers spiral in the same relation such that rotation of the vertical augers conveys feed material upwardly toward a top wall of the tank where the material then flows laterally toward the opposite side walls and forwardly and rearwardly toward the front and rear walls. As disclosed and illustrated in the High et al patent, the mixing apparatus also includes a rotatably-mounted horizontal top auger having flights that spiral in reversed relation such that rotation of the top auger conveys feed material away from the vertical augers and toward the front and rear tank end walls.
Thus, in the above-described mixing apparatus, portions of the feed material follows a plurality of generally circuitous paths within its tank to achieve thorough mixing thereof. Overall the above-described mixing apparatus has been very successful in producing a mixed and blended livestock feed of high quality. However, the apparatus does have certain limitations fostered primarily by the mechanical drive arrangement employed to rotatably drive its various augers.
One limitation is manifested in the positional relationship between the lower end of the flight of one of the vertical augers and the bottom of the flight of the bottom auger. The end of the one vertical auger terminates in a generally tubular housing portion connected to and protruding downwardly from the exterior of the one side wall adjacent to the bottom of the tank at the intermediate location of the vertical augers. Bevel gears coupling the one vertical auger and other components of the mechanical drive arrangement are provided in the bottom of the tubular housing portion. The space required for the bevel gears means that the lower end of the one vertical auger flight must begin at an elevation displaced above the bottom of the tubular housing portion which also displaces it above the bottom edge of the bottom auger flight.
Because of this positional relationship, an upwardly sloping transition member is provided to extend from below the bottom auger upwardly to the start of the flight of the vertical auger. The bottom auger is thus required to push feed material along the inclined path defined by the transition member upwardly to the start of the vertical auger flight. However, the bottom auger is only supported at its opposite ends. Such pushing action causes the bottom auger to flex and bow in a transverse relation to its axis, resulting in an increase in wear and reduction in the useful life of the bottom auger. Also, the addition of molasses to the feed material frequently results in material build up on the inclined transition member which causes added flexing and bowing of the bottom auger.
Another limitation relates to the fixed ratio established between the rotational speeds of the various augers by employment of the mechanical drive arrangement. The mechanical drive arrangement will not accommodate adjustment of the relative speed relationships between the augers.
Consequently, a need exists for improvements to the mixing apparatus of the aforementioned patents in order to eliminate these limitations.